Quake? No problem, our nuke ‘shock-absorbers’ can handle it: Eskom

Eskom says it is not worried about the “shock absorbers” at its Koeberg facility ahead of a possible “life extension” beyond 2024.   

Recent seismic events felt in Cape Town sparked concerns about the ageing plant, which is due for decommissioning in 2024, 40 years after coming online. In particular there are questions about the shelf life of key plant components, such as an earthquake “raft” safety feature that allows the plant to absorb seismic shocks – the so-called shock absorbers.

However, Eskom says it remains confident that the National Nuclear Regulator will approve its application to extend Koeberg’s lifespan.

“The seismic raft design which provides the seismic 'shock absorber' is one of numerous plant systems, structures and components that are monitored routinely through the extensive plant inspection, monitoring and maintenance programmes,” Eskom said in response to Sunday Times Daily queries.

“These programmes ensure that all the plant’s safety features remain fit for purpose throughout the plant life by detecting and correcting any degradation, thereby ensuring safe ongoing operation.

“As a result of these programmes, certain components have been upgraded or replaced as part of the life-cycle management of the power station, and this will continue for as long as the station operates. Examples of these include the low-pressure turbines, the generator transformers, the generator stator windings, the turbine control system and the reactor control rod control system,” the power utility said.

Eskom continues to work closely with the Council for Geoscience to understand the seismic hazards.

The power utility did not clarify whether there was a particular warranty period for the seismic raft safety feature.

Last month, Eskom took delivery of the first of six huge new 380-ton steam generators, another key component of the plant’s planned R20bn facelift. The delivery was partly overshadowed by a rare offshore 6.2 Richter scale earthquake and a smaller tremor within a 24-hour period in late September, both felt in some parts of Cape Town – but only just.

The seismic wobble coincided with news that the Council for Geoscience is studying a possible new regional fault area in Table Bay, which may be linked to two other known regional fault zones.

Eskom said the latest geoscience findings would be incorporated into the mandatory seismic safety reports, and that they did not signal any cause for concern.

“Eskom continues to work closely with the Council for Geoscience to understand the seismic hazards and on a continual basis confirm that this is catered for by the Koeberg design,” it said.

“The studies that are required to be performed as part of the justification for extending the operating licence of Koeberg include a review of the seismic hazard associated with the Koeberg site. This would include the latest known seismic data for the area.”

Peter Becker, director of watchdog group Koeberg Alert, said the public might be more willing to believe Eskom’s safety assertions if only the power utility would share key safety information, such as the plant’s seismic hazard report.

In response, Eskom said not all information could be shared, as per the Promotion of Access to Information to Act: “Where Eskom receives a request, every effort is made to obtain and provide the information, which is shared through the PAIA process. If as per the exclusions in the act the information cannot be shared, the requestor has to be informed.”